Outrigger with Locking Mechanism

ABSTRACT

An outrigger for connecting to an external bone fixation clamp comprises an elongated member having a length, a proximal end and a distal end, the distal end having a threaded portion. The outrigger also comprises a connecting member operably associated with the elongated member, the connecting member having a tightening portion at a proximal end and a gripping portion at a distal end, the gripping portion having a greater diameter than the tightening portion. The outrigger also comprises a slide lock disposed about the threaded portion, the slide lock being longitudinally movable along the length of the threaded portion and having a non-smooth engagement surface configured to engage a non-smooth surface of the external bone fixation clamp in order to prevent rotation of the elongated member relative to the external bone fixation clamp.

PRIORITY CLAIM

The present application is a Continuation Application of U.S. patentapplication Ser. No. 11/114,554 filed on Apr. 25, 2005 entitled“Outrigger With Locking Mechanism.” The disclosure of the aboveapplication is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an outrigger for use in an externalfixation system and, in particular, a locking mechanism which preventsloosening of the outrigger after surgery.

BACKGROUND OF THE INVENTION

Outriggers typically form part of an external fixation system and areusually attached to a clamp which holds one or more wires, pins, screws,rods, bars and/or rings. Threads on one end of the outrigger have beenused to attached the outrigger to a clamp. Such a construction, however,may allow the outrigger to loosen and/or separate from the clamp after asurgical procedure. Therefore, it is desirable to have an outriggerincorporating a locking mechanism which prevents the outrigger fromloosening and/or separating from a clamp after surgery.

SUMMARY OF THE INVENTION

The present invention relates to an outrigger which may include anelongated member having a distal end, a proximal end and a connectingportion proximate the distal end; a moveable member operably associatedwith the distal end; and a slide lock. In one embodiment, the connectingportion may be a threaded portion.

The threaded portion may have a keyed portion (e.g., at least one flatside) and may be screwed into a threaded opening in a clamp. The slidelock may have an opening therethrough which may be keyed or configuredsuch that it can translate along the threaded portion but not rotateabout the threaded portion. In one embodiment, the slide lock may havean opening therethrough with at least one flat portion which maycooperate with at least one flat side of the threaded portion.

The moveable member may be positioned proximal the slide lock such thatthe slide lock may be positioned between the moveable member and aclamp. The moveable member may engage the threaded portion of theelongated member such that the moveable member may move distally andproximally along the threaded portion. In one embodiment, the movementmember may be a nut having an opening with internal threads, which mayengage the threaded portion. Rotation of the nut may move the nuttowards and/or away from the slide lock. Movement of the moveableportion towards the slide lock may push the slide lock distally suchthat the slide lock may translate along the threaded portion towards aclamp.

The slide lock may have an engagement portion such as, for example, aserrated, knurled or rough surface. As the moveable member moves theslide lock distally along the threaded portion, the engagement portionof the slide lock may engage a surface of a clamp, which may be aserrated, knurled or rough surface. Contact between the engagementportion of the slide lock and the surface of the clamp may preventrotational movement of the slide lock relative to the clamp. Because ofthe configuration, such as, for example, the keyed configuration of theopening in the slide lock, rotational movement of the outrigger withrespect to the slide lock and, consequently, the clamp may also beprevented. In one exemplary embodiment, at least one flat portion of theslide lock may engage the flat, unthreaded side of the threaded portionto prevent rotation of the outrigger with respect to the slide lock and,consequently, rotation of the outrigger with respect to the clamp.

In one embodiment, the threaded portion of the elongated member of theoutrigger may have a groove for receiving a washer, which may limit theextent the threaded portion may be screwed into a clamp. The washer mayalso keep the moveable portion and slide lock from sliding off theelongated member so that the elongated member, moveable portion andslide lock may be attached to a clamp as an assembly that cannot bereadily disassembled, or may only be disassembled by breaking one ormore pieces of the assembly.

In use, the elongated member, moveable member and slide lock may beconnected together. The moveable member may be positioned proximate theslide lock such that the slide lock may be located between the moveablemember and a clamp. The threaded portion may be screwed into a threadedopening in a clamp. In an embodiment incorporating a washer around thethreaded portion, the threaded portion may be screwed into the clampuntil the washer contacts the clamp. Thereafter, the moveable member maybe moved in a distal direction towards the slide lock and the clamp. Themoveable member, in turn, may move the slide lock towards the clampuntil the engagement portion of the slide lock engages a portion of theclamp. The moveable member may be tightened to fix the position of theslide lock and, consequently, the elongated member relative to theclamp.

In one embodiment, a method for inserting an outrigger to a clamp of anexternal fixation system may comprise providing an outrigger which mayhave an elongated member having a length, a distal end, a proximal endand a connecting portion on the distal end, wherein the connectingportion may have a keyed portion; a moveable member operably associatedwith the elongated member which may be moveable along the elongatedmember; and a slide lock which may be disposed about the elongatedmember, the slide lock may have a keyed portion and an engagementsurface, wherein the keyed portion of the connecting portion and thekeyed portion of the slide lock may be operably associated with eachother to permit longitudinal movement of the slide lock along the lengthof the elongated member while preventing rotation, and wherein theengagement surface of the slide lock may be configured to engage aportion of a clamp. The method may further comprise providing a clampwhich may have an opening and an engagement portion positioned proximatethe opening, moving the connecting portion of the elongated member intothe opening of the clamp, engaging the connecting portion to the clamp,moving the moveable member on the connecting portion to move the slidelock towards the clamp, and engaging the engagement surface of the slidelock with the engagement portion of the clamp. Moreover, in anembodiment where the connecting portion may further comprise a groovefor receiving a washer, the method may also comprise moving theconnecting portion into the opening until the washer contacts theengagement portion of the clamp.

In an embodiment where the connecting portion may be a threaded portion,the method may further comprise providing a clamp which may have athreaded opening and an engagement portion positioned proximate theopening, screwing the threaded portion of the elongated member into thethreaded opening of the clamp, moving the moveable member on thethreaded portion to move the slide lock towards the clamp, and engagingthe engagement surface of the slide lock with the engagement portion ofthe clamp. Furthermore, in an embodiment where the threaded portion mayfurther comprise a groove for receiving a washer, the method may alsocomprise screwing the threaded portion into the threaded opening untilthe washer contacts the engagement portion of the clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be better understood by reference to thefollowing drawings, wherein like references numerals represent likeelements. The drawings are merely exemplary to illustrate certainfeatures that may be used singularly or in combination with otherfeatures and the present invention should not be limited to theembodiments shown.

FIG. 1 is a side view of an exemplary embodiment of the outrigger of thepresent invention;

FIG. 2 is a side view of an alternative exemplary embodiment of theoutrigger of FIG. 1;

FIGS. 3A-C are side views of an exemplary embodiments of a component ofthe present invention;

FIGS. 4A and 4B are perspective views of an exemplary embodiment ofadditional components of the present invention;

FIG. 5 is a perspective, exploded view of an exemplary embodiment of aclamp used in an external fixation system;

FIG. 6 is a top view of the clamp of FIG. 5; and

FIG. 7 is a perspective view of an exemplary embodiment of an externalfixation system incorporating the devices of FIGS. 1, 2 and 5.

DETAILED DESCRIPTION

As shown in FIG. 1, the outrigger 1 may include an elongated member 2having a distal end 3, a proximal end 4 and a connecting portion 6proximate the distal end 3; a moveable member 8 operably associated withthe distal end 3; and a slide lock 10. It should, however, be understoodthat those of ordinary skill in the art will recognize manymodifications and substitutions which may be made to various elements ofthe present invention.

The elongated member 2, moveable member 8 and slide lock 10 may be madeof any material, preferably, a biocompatible material such as, forexample, metal (e.g., stainless steel, titanium, aluminum), plastic,rubber, ceramic, an alloy of two or more materials, or a compositematerial (i.e., made up of two or more materials). The elongated member2, moveable member 8 and slide lock 10 may be made of the same ordifferent materials.

The elongated member 2 may be straight or bent at an angle. Asillustrated in FIGS. 1 and 2, the elongated member 2 may be bent at anangle θ of, for example, between about 90 degrees and about 180 degrees,preferably, between about 115 degrees and about 170 degrees and, mostpreferably, between about 140 degrees and about 160 degrees. Theelongated member 2 may be solid or hollow.

In one embodiment, the connecting portion 6 may be a threaded portion.The threaded portion 6 may have a keyed portion 12 or may otherwise havea non-circular cross-section for reasons that will be explained below.As shown in FIGS. 1 and 3A, the keyed portion 12 of the threaded portion6 of the elongated member 2 may take the form of at least one flat side12. In a preferred embodiment, the threaded portion 6 may have twodiametrically opposed flat sides 12. Moreover, the threaded portion 6may also have a circumferential, unthreaded groove 14 for receiving awasher 16. The washer 16 may limit the extent to which a surgeon mayscrew the outrigger 1 into a clamp (e.g., clamp 100 of FIGS. 5 and 6).In addition, the washer 16 may keep the moveable member 8 and the slidelock 10 from sliding off the elongated member 2 so that the elongatedmember 2, moveable member 8 and the slide lock 10 may be attached to aclamp as an assembled, single unit. The washer 16 may be made of any ofmetal (e.g., stainless steel, titanium, aluminum), plastic, rubber,ceramic, an alloy of two or more materials, or a composite material(i.e., made up of two or more materials). In a preferred embodiment, thewasher 16 may be made of metal.

It will be appreciated by those skilled in the art that the connectingportion 6 may be configured in any manner so long as the connectingportion 6 may prevent the elongated member 2 from being removed from aclamp (e.g., clamp 100, FIGS. 5 and 6) and may allow for attachment ofthe moveable member 8 to the elongated member 2. In one embodiment, thelower portion 6 b of the connecting portion 6 may be unthreaded and mayhave a portion (e.g., a flat surface, an indentation, an opening), whichmay be engaged by a set screw 19 (FIG. 3B) positioned through a clamp.The set screw 19 may hold the elongated member 2 to the clamp. Inanother embodiment, the connecting portion 6 may comprise a retractablemember (e.g., ball detent) 21 (FIG. 3C) which may be in a retractedposition as the connecting portion 6 is inserted into an opening of aclamp and which may expand to fix the elongated member 2 to the clamponce the connecting portion 6 has been inserted a distance into theopening of the clamp.

A moveable member 8 may be attached to the threaded portion 6. As shownin FIG. 4A the moveable member 8 may have an opening 17 with internalthreads 18. The internal threads 18 may engage external threads 6 a onthe threaded portion 6 such that rotation of the moveable member 8 in afirst direction may result in the moveable member 8 moving towards thedistal end 3 and rotation of moveable member 8 in a second direction mayresult in the moveable member 8 moving towards the proximal end 4. Themoveable member 8 may also have a gripping portion 20 and a tighteningportion 22. The gripping portion 20 may be used by a surgeon to tightenthe moveable member 8 to a clamp using the surgeon's fingers. Thegripping portion 20 may have numerous grooves or other surfaceroughening or enhancements to improve a surgeon's grip on the moveablemember 8. To further tighten the moveable member 8 to a clamp, thesurgeon may use a tool to engage tightening portion 22. The tighteningportion 22 may be any shape (e.g., square, hexagon, octagon). It will beappreciated by those skilled in the art that the moveable member 8 maybe any component which may be moved up and down the threaded portion 6and fixed in position on the threaded portion 6, and may comprise a nut.

The slide lock 10 (FIG. 4B) may be positioned proximate the moveablemember 8 and, in particular, may be positioned between the moveablemember 8 and a clamp. The slide lock 10 may have an opening 24 which mayreceive the threaded portion 6. The opening 24 may be keyed or otherwiseconfigured to cooperate with the keyed portion of the threaded portion 6so that the slide lock 10 may translate along the threaded portion 6,but not rotate thereabout. In one embodiment, the opening 24 may have atleast one flat portion 26 which may cooperate with the at least one flatside 12 of the threaded portion 6 such that the slide lock 10 maytranslate along the threaded portion 6, but not rotate thereabout. In apreferred embodiment, the slide lock 10 may have two diametricallyopposed flat portions 26 to engage two diametrically opposed flat sides12 of the threaded portion 6. It should be noted, however, that anyconfiguration of the slide lock 10 and threaded portion 6 may be used solong as the slide lock 10 may be prevented from rotating with respect tothe threaded portion 6.

The slide lock 10 may have an engagement portion 28 such as, forexample, a serrated, knurled or rough surface. The engagement portion 28of the slide lock 10 may be integral with the slide lock 10 or may be aseparate piece. The engagement portion 28 may contact a portion of aclamp. In one embodiment, the engagement portion 28 may be serrated andmay engage the serrations 30 on either side of a clamp 100 (FIGS. 5 and6). It will be appreciated that the engagement portion 28 of the slidelock 10 may be configured to include a surface which may providesufficient friction when engaged with a surface of a clamp so as toprevent the slide lock 10 from moving (e.g., rotating) with respect tothe clamp. Although shown as a relatively flat disc, the slide lock 10may take the form of other shapes.

In use, the elongated member 2, moveable member 8 and slide lock 10 maybe operably connected to each other. The threaded portion 6 of theelongated member 2 may be twisted or screwed into a threaded opening ina clamp. In an embodiment that includes the optional washer 16, theelongated member 2 may be screwed into the clamp until the washer 16engages the clamp. The moveable member 8 may be rotated such that themoveable member 8 moves towards the clamp and, thus, may move the slidelock 10 towards the clamp. The keyed configuration of the threadedportion 6 and the slide lock 10 may allow the slide lock 10 to translatewithout rotating. For example, the engagement of the at least one flatside 12 of the threaded portion 6 with the at least one flat portion 26of the slide lock 10 may result in the slide lock 10 translating alongthe threaded portion 6, while preventing the slide lock 10 from rotatingabout the threaded portion 6. As the slide lock 10 moves closer to theclamp, the engagement portion 28 of the slide lock 10 may engage asurface of the clamp. In an embodiment where the engagement portion 28may be serrated, these serrations may engage corresponding serrations onthe clamp. When the slide lock 10 engages the clamp, the slide lock 10may be fixed or locked relative to the clamp and rotation between theslide lock 10 and the clamp may be prevented. Moreover, the engagementbetween the at least one flat side 12 and the at least one flat portion26 may prevent the elongated member 2 from rotating with respect toslide lock 10 and, consequently, also with respect to the clamp. Such aconstruction may help prevent the outrigger 1 from loosening orseparating from a clamp after surgery.

As shown in FIG. 7, the outrigger 1 may be used to connect variouscomponents including, for example, a clamp 200 and rod 300, to a pinclamp 100, which may engage pins or wires 400 inserted in a bone 500.The outrigger 1 may be used as a component of an external fixationdevice.

While the foregoing description and drawings represent the preferredembodiments of the present invention, it will be understood that variousadditions, modifications and substitutions may be made therein withoutdeparting from the spirit and scope of the present invention as definedin the accompanying claims. In particular, it will be clear to thoseskilled in the art that the present invention may be embodied in otherspecific forms, structures, arrangements, proportions, and with otherelements, materials, and components, without departing from the spiritor essential characteristics thereof. One skilled in the art willappreciate that the invention may be used with many modifications ofstructure, arrangement, proportions, materials, and components andotherwise, used in the practice of the invention, which are particularlyadapted to specific environments and operative requirements withoutdeparting from the principles of the present invention. The presentlydisclosed embodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims, and not limited to the foregoingdescription.

1-16. (canceled)
 17. An outrigger for connecting to an external bonefixation clamp, comprising: an elongated member having a length, aproximal end and a distal end, the distal end having a threaded portion;a connecting member operably associated with the elongated member, theconnecting member having a tightening portion at a proximal end and agripping portion at a distal end, the gripping portion having a greaterdiameter than the tightening portion; and a slide lock disposed aboutthe threaded portion, the slide lock being longitudinally movable alongthe length of the threaded portion and having a non-smooth engagementsurface configured to engage a non-smooth surface of the external bonefixation clamp in order to prevent rotation of the elongated memberrelative to the external bone fixation clamp.
 18. The outrigger of claim17, wherein the tightening portion is formed with a cross-sectionalshape selected to permit engagement thereof with a driver tool.
 19. Theoutrigger of claim 18, wherein the cross-sectional shape is one ofsquare, hexagonal and octagonal.
 20. The outrigger of claim 17, whereinthe connecting member is operably associated with a proximal end of thethreaded distal end.
 21. The outrigger of claim 17, wherein theengagement surface is serrated.
 22. The outrigger of claim 17, whereinthe engagement surface is knurled.
 23. The outrigger of claim 17,wherein the slide lock comprises an opening extending therethrough, theopening being configured to cooperate with the threaded portion.
 24. Theoutrigger of claim 17, wherein the threaded portion is keyed.
 25. Theoutrigger of claim 24, wherein the slide lock is keyed.
 26. Theoutrigger of claim 17, wherein the threaded portion comprises acircumferential non-threaded groove for receiving a washer.
 27. Theoutrigger of claim 17, wherein a distal portion of the elongated membercomprises a feature configured to receive a locking mechanism, thelocking mechanism being insertable into the feature at an angle relativeto a longitudinal axis of the elongated member.
 28. The outrigger ofclaim 27, wherein the feature is one of a flat surface, an indentationand a lateral opening in the distal portion and the locking mechanism isa set screw.
 29. The outrigger of claim 27, wherein the feature is anopening housing a retractable element configured to apply a radiallyexpansive locking force to the bone fixation clamp when the elongatedmember is operably connected thereto.
 30. A system for external bonefixation, comprising: an outrigger comprising: an elongated memberhaving a length, a proximal end and a distal end, the distal end havinga threaded portion; a connecting member operably associated with theelongated member, the connecting member having a tightening portion at aproximal end and a gripping portion at a distal end, the grippingportion having a greater diameter than the tightening portion; and aslide lock disposed about the threaded portion, the slide lock beinglongitudinally movable along the length of the threaded portion andhaving a non-smooth engagement surface; and a clamp configured to engageat least one bone fixation element, the clamp having a first openingconfigured to receive the threaded portion of the outrigger, an outerperiphery of the first opening having a non-smooth surface configured toengage the non-smooth surface of the slide lock to prevent rotation ofthe outrigger relative thereto.
 31. The system of claim 30, furthercomprising: a bone fixation element selected from the group consistingof a screw, pin, wire, rod, bar and ring.
 32. The system of claim 27,further comprising: a groove extending through the threaded portion ofthe elongated member.
 33. The system of claim 32, further comprising: awasher received in the groove.